The present invention relates to portable electronic devices and to antenna arrangements to enable wireless transfer of data to and/or from such devices and, in particular, to such an antenna arrangement attached to or incorporated into a pair of trousers or other garment.
It is known to provide an antenna in or attached to a garment, for example for use in a mobile telecommunications system. One example of this is given in EP-A-0 637 094 to Matsushita which describes an antenna comprising metal antenna elements in the form of conductive plates formed on opposite sides of a dielectric slab; the antenna is intended for mounting on a human shoulder, and the rigidity of the dielectric slab prevents deformation of the antenna. However, the rigidity also results in the antenna being uncomfortable and inconvenient to wear, as well as rendering it somewhat obtrusive. A more flexible construction of wearable antenna for such applications is described in our commonly assigned United Kingdom patent application no.9927842.6 (PHB34417) whilst the flexible construction makes the antenna more suited for incorporation into garments for everyday wear, the need for insulator spacing of plates creates a certain thickness for the antenna which limits its applications.
It is also known to provide an antenna suitable for at least partial incorporation into a garment from U.S. Pat. No. 5,825,327 (Krasner) which describes an arrangement of GPS receiver and GPS transmitter, communication antenna and communication transmitter incorporated into a jacket and/or a pair of trousers with the antennae being in the form of flexible strip antenna devices sewn to the inner or outer surface of the garment. The particular consideration of Krasner is the avoidance of line-of-sight problems which can affect the acquisition and tracking of GPS satellite signals.
A further example of an antenna incorporated within a garment is given in United Kingdom patent application GB-A-2 183099 (UK Secretary of State for Defense). The antenna described comprises a tubular member of flexible electrically-conducting material fitted as a liner within the sleeve of a jacket (or other upper body garment) or within the leg of a pair of trousers.
What is not considered is how the performance of the antennae in GB-A-2 183099 and U.S. Pat. No. 5,825,327 (Krasner), and other wearable antenna constructions, might be improved and/or adapted for optimum performance.
Accordingly, it is an object of the present invention is to provide an antenna capable of unobtrusive incorporation into a garment and having improved performance.
In accordance with the present invention there is provided a garment comprising an antenna and means for connection of the same to a portable electronic device to permit wireless communications of said device via said antenna;
wherein the garment is shaped to be worn about the lower body of a user and the antenna is a longitudinal conductive element attached to the garment in such an orientation as to be close to the ground and to extend substantially vertically when a wearer of the garment is in a standing position.
As will be described in greater detail hereinafter with reference to FIGS. 1 to 3 of the accompanying drawings, the applicants have recognised that, by arraying the elements of an antenna in vertical orientation but close to the ground (for example in a dress, skirt, pair of trousers or full length coat), the effect of a flat earth planexe2x80x94i.e. the groundxe2x80x94may be utilised to give enhanced performance.
The antenna might be a single conductor or may comprise a plurality of longitudinal conductive elements spaced about the lower portion of the garment and positioned in substantially parallel alignment. Such an arrangement also counters the electric field reduction effect of the human body, as will also be described in greater detail hereinafter.
The or each antenna element may be attached to an interior surface of the garment, or attached to an exterior surface of the garment, or be concealed within a seam of the garment, or a combination of some or all of these arrangements may be utilised. Alternatively, the or each antenna element may comprise a track of flexible conductive material deposited on a surface of the garment, or may comprise one or a plurality of conductive threads interwoven with the material of the garment. Indeed, substantive portions of the garment may be woven from conductive thread or otherwise assembled from conductive material such as to provide a large area for the antenna element.
The or each antenna may comprise a monopole element with a feed connection at the upper end thereof, or it may comprise a dipole with a feed connection joining a matched pair of antenna elements. This latter arrangement is particularly suited where the garment is in the form of a pair of trousers with each of said matched pair of elements being disposed down a respective leg of the trousers, although it will be recognised that such symmetry is not mandatory.
The said means for connection to the portable electronic device may comprise a conventional plug and socket or might comprise one or more conductive press stud connectors in electrical contact with the or each antenna element. For enhanced usability, the garment may further comprise a pocket for reception of the said portable electronic device adjacent said antenna.
As will be described, the form of electronic device may vary, with the wireless link capability allowing devices previously required to be of unitary (i.e. hard-wired) construction to instead take up a distributed arrangement with separate components spread amongst the garments of a user (or possibly even of several users). By use of the invention as the antenna in mobile telecommunications equipment, the remainder of the handset can be made smaller and lighter than was previously possible through separation of the component parts, particularly as the overall size of many mobile telephone handsets is constrained by the size of the antenna assembly used. Such an antenna is intended to be flexible and lightweight and one that does not impede the movements of the user. The mobile telecommunications equipment may be a mobile telephone or a pager or other portable devices accessing a single base-station or forming a part of a wireless Local Area Network (LAN).